1. Field of the Invention
The present invention relates to a ventilation fan, and particularly to a ventilation fan mounting structure.
2. Description of the Related Art
Generally, the conventional ventilation fan comprises a quadrate ventilation fan frame and parts such as a snail shell and a fan blade motor which are mounted inside the ventilation fan frame.
In order to mount the ventilation fan, a bracket assembly is provided in the prior art. FIG. 1A is a schematic view of the bracket assembly, and FIG. 1B is a schematic view showing mounting of the bracket assembly when only one opening having the same size as the ventilation fan frame is reserved in a ceiling. As shown in FIGS. 1A and 1B, the bracket assembly 4 is composed of a first bracket 5, a second bracket 6, and a quadrate ventilation fan mounting frame 9. Each of the first bracket 5 and the second bracket 6 has a U shape and is composed of two side members 1 opposite to each other and a connection member 2 connecting the two side members 1. In other words, the two side members 1 are located on both sides of the connection member 2. An open groove 7 is formed by folding upper and lower edges of each of a pair of opposing side members of the ventilation fan mounting frame 9 towards an outside of the ventilation fan mounting frame 9 to be opposite to each other.
After the first bracket 5 and the second bracket 6 are respectively inserted into the grooves 7 from both ends of the grooves 7 of the ventilation fan mounting frame 9 so as to be engaged integrally, a quadrate is formed by the connection members 2 and the side members 1 of the first bracket 5 and the second bracket 6 around the ventilation fan mounting frame 9. Engagement parts 8 for mounting the ventilation fan frame are disposed on the opposite side members of the ventilation fan mounting frame 9 where the grooves 7 are disposed, accordingly, the ventilation fan frame can be mounted in the ventilation fan mounting frame 9 through the engagement parts 8.
If a user wants to replace the ventilation fan when the ceiling and the ventilation fan have been mounted, when mounting a new ventilation fan with a bracket assembly such as that in the abovementioned prior art, a louver and the old ventilation fan are firstly removed, and here, only an opening 1000 having the same size as the ventilation fan frame is reserved in the ceiling. Provided that the ceiling is not detached, the user needs to pass the bracket assembly 4 though the opening 1000 of the ceiling and fix it to joists, and then pass a new ventilation fan frame through the opening 1000 of the ceiling and mount it in the ventilation fan mounting frame 9.
The ceiling opening 1000 is equivalent in size to a cross section of the ventilation fan frame and the bracket assembly 4 is greater than the cross sectional area of the ventilation fan frame. In other words, the bracket assembly 4 is greater than the ceiling opening 1000 in size. Therefore, when the user passes the bracket assembly 4 through the ceiling opening 1000, he needs to position the connection members 2 of the first bracket 5 and the second bracket 6 relatively obliquely while the side members 1 on both sides of the connection members 2 are also relatively obliquely positioned. Only in this way can he insert the bracket assembly 4 into the ceiling opening 1000. In other words, only when one of the connection members 2 of the first bracket 5 and the second bracket 6 is lower than the other, and one of the side members 1 on both sides of the connection members 2 is lower than the other, can the bracket assembly 4 be inserted into the ceiling opening 1000.
When a distance between the ceiling and a roof is set to be small, after being obliquely inserted into the ceiling opening 1000, the bracket assembly 4 will come into contact with the roof and be blocked by the roof. In this case, the bracket assembly 4 cannot be restored to a horizontally positioned state due to insufficient space and thus the mounting cannot be continued.